A device of a display screen is made to give an atmosphere of a real store for a virtual store such as an online store which sells products on the Internet or a purchase procedure is completed by way of clicking of a mouse in order to improve users' convenience and promote sales. Patent Document 1 discloses online store visitors' activity displaying method of displaying an existence of a first visitor to an online store, receiving information related to an activity of a second visitor, and displaying the activity of the second visitor to the first visitor.